It is sometimes necessary to provide a driven hinge for driving and powering the movement of one hinge section relative to another.
For example, certain aircraft require a folding wingtip that must be locked in place while in flight and also on the ground with the wings folded. Carrier-based aircraft, such as the F-18 and F-35, may require folding wingtips to minimize the space required for aircraft storage.
The present F-18 wingfold utilizes a compound planetary hinge rotary actuator to form the hinge lock. One example of this is disclosed in U.S. Pat. No. 6,783,478. This device has the inherent capability to handle the loads in the extended and folded positions, but is relatively large, heavy and expensive to manufacture. The F-35, with a thinner wing, cannot accommodate this type of hinge design due to a reduced envelope. Hence, a spline lock concept of driven hinge, such as shown in U.S. Pat. No. 6,032,418, has been developed. This provides a smaller-profile hinge lock, and an overall lighter design. However, it also requires tighter tolerances and difficult machining of the hinge actuator parts, as well as the mating aircraft structure.
Accordingly, it would be generally desirable to provide an improved powered hinge that would have an automatic locking feature at either end of the permissible relative angular displacements of its hinge sections, that would be lighter in weight, and that would be less expensive to manufacture.